[Jadware]

I'm trying to retrofit a late model ultrawide backup camera to a different vehicle and could use some help/advice.

The camera part number is 90874903 (interchanges with a half dozen other numbers) and is very common on late model BMW's for rear, front, and even side cameras. The pinouts and image of the camera are attached below.

The diagram says the signal is FBAS which sounds like CVBS a.k.a. component standard def signal. But in all the other descriptions and diagrams, the camera signal appears to be Ethernet with a TXD/RXD line pair. Some other language implies that the TRSVC All Around Camera Vision module is what decodes all the camera feeds into a signal for the headunit, using a video switch (VSW).

How do I hook this camera up to an RCA input?

[Billfitz]

I assume you have a screen that accepts RCA input. I'd just buy a camera that has RCA output. Choices abound and they're all very inexpensive.

[Jadware]

I'm also trying to tap into existing cameras already installed in a car

[Jadware]

After more investigation, it might be a protocol called Ethernet AVB

[jkwhar]

up to 2013, the rear view/surround view used TRSVC ECU with 4 pin per camera. 2014 and newer uses ICAM ECU.